I was toying around with writing an SCP about a really messed up fountain of youth. It might have some religious statue or something on it (consider the exact aesthetics to be TBD). The water (which infinity replenishes to keep the water level the same) would make anyone who drinks it turn into a turn into a grotesque monstrotiy. Each one would be unique to the person but they would all be loosely based on that persons greatest sin. So glutton would turn into a giant fat guy (think 500 lb) with many arms, a few extra mouths and the uncontrollable urge to eat everything it can see. Anger would turn into a hulk like being with some kind of fire breath/big claws or something. Greed would be a small fast skittley thing that steals anything other people find valuable. Etc.

It's original purpose was to test crusaders for purity of the soul. In theory the pure wouldn't turn and the unpure could be used as weapons but it all went horribly wrong and the creations killed everyone who knew about it.

The exact details are TBD. This is mostly to test the waters and see if this idea is worth perusing.

I don't think it sounds very promising. Monsters themed on the 7 deadly sins are a pretty common trope, and it seems like this article would mostly be a list of basic monster types (gluttony eats stuff, lust is seductive but drains life, etc.) which is a type of article that tends to do poorly because it's usually stuff readers have seen a bunch of times in other media like comics and video games. I think it would be hard to do this in a way that doesn't just dump a bunch of exposition on the reader - "this does this and that does that and this does the other and it's all because of the crusades."

In general anything that's themed off the 7 deadly sins is going to be a tough sell because it's not original; the sins have been done to death as a motif. I can imagine a successful character-based article about a guy in containment who drank from a fountain to become stronger and turned into a monster instead, and what that was like for him, but that seems pretty far from what you have in mind so far.